JPH0354726A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To precisely decide the timing of the recording, the reproducing or the erasing of information by providing an advance recording area detection circuit and a timing control means which controls the timing of the recording or the reproducing of the information based on an advance recording area detection signal. CONSTITUTION:The advance recording area detection signal G is transmitted to a timing control circuit 20 functioning as the timing control means from an information reproducing circuit 17. Simultaneously, a synchronization detection signal H generated by a synchronization detection circuit 18 based on a sector mark signal F is transmitted to the timing control circuit 20. Based on them, a reproducing timing signal I is outputted to the information reproducing circuit 17. On the other hand, a recording and erasing timing signal J is outputted to an information recording and erasing circuit 21. Besides, a waveform shaping circuit 22 and the advance recording area detection circuit 24 consisting of a retriggerble pulse generation circuit 23 are included in the information reproducing circuit 17 and a pre-format part 13 functioning as the advance recording area where a sector mark or the like is recorded in advance is detected. Thus, the timing of the recording, the reproducing or the erasing is precisely decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information recording/reproducing method for recording or reproducing information in various types of memory elements, such as magneto-optical disks, on which information such as address information is recorded in advance. The present invention relates to a device, and more specifically to controlling the timing of recording or reproducing information.

[Conventional technology]

A magneto-optical disk usually uses a magnetic thin film having perpendicular magnetic anisotropy as a recording medium, and records, reproduces, and erases data by irradiating the thin film with a laser beam focused to about 1 μm. Specifically, recording and erasing are accomplished by performing magnetization reversal using an external magnetic field, taking advantage of the fact that the coercive force decreases due to an increase in the temperature of the light condensing portion. Further, reproduction is achieved by utilizing the rotation of the polarization plane of the laser beam in the magneto-optical effect and detecting this with an analyzer.

By the way, each track of the above-mentioned magneto-optical disk is divided into a plurality of sectors in the circumferential direction, and sector marks and address information are formatted in the form of uneven pits in the leading area of each sector. It is conceivable to record, reproduce, and erase the magneto-optical signal in units of sectors by using the remaining area as the recording area for the magneto-optical signal. In that case, it is necessary to perform timing control so that recording, reproduction, and erasing are performed in the recording area of the magneto-optical signal other than the above-mentioned preformat 1 section.

FIG. 21 shows a conventional information recording and reproducing apparatus for recording and reproducing information on a magneto-optical disk using the above-described method. A reproduction signal A is output from the information reproduction circuit 1, and this reproduction signal A is input to the synchronization detection circuit 2. The synchronization detection circuit 2 is capable of detecting synchronization on a sector-by-sector basis from a signal such as a sector mark portion, which is a part of the reproduced signal A, for example.

The synchronization detection signal B output from the same brightness detection circuit 2 is input to the timing control circuit 3, and the timing control circuit 3 performs timing-based talling based on the synchronization detection signal B, and when playing back information. A reproduction timing signal C is sent to the reproduction circuit 1, while a recording and erasing timing signal E is sent to the information recording and erasing circuit 4 during recording or erasing. As a result, information is recorded, reproduced, and erased in the recording area of the magneto-optical signal in each sector. Note that the synchronization detection by the synchronization detection circuit 2 is performed separately from the reproduction of information, so that the synchronization detection is not disturbed by the reproduction timing signal C.

[Problems to be Solved by the Invention] However, in the device shown in FIG. 21, timing control is performed using only synchronization detection, and therefore errors may occur in synchronization detection or deviations in detection time by the synchronization detection circuit 2, etc. There were cases where accurate timing control could not be performed. for example,
p L L (Phase
Errors occur in timing control due to causes such as the read gate signal of Locked Loop becoming inaccurate, the pull-in operation becoming impossible, and ronk being easily misaligned. As described above, the conventional method has a problem in that the reliability of recording, reproducing, and erasing information is reduced. Also, if an error occurs in synchronization detection, AG C (Automatic Gain Con
trol), etc., was also problematic.

[Means for Solving the Problems] In order to solve the above problems, an information recording and reproducing apparatus according to the present invention records or reproduces information on a memory element, and provides a method for recording and reproducing information on a memory element in advance. A pre-recorded area detection circuit that detects a pre-recorded area in which information is recorded; and a timing control means that controls the timing of recording or reproducing information based on a pre-recorded area detection signal output from the pre-recorded area detection circuit. It is characterized by having the following.

[For production]

As described above, in the present invention, the timing of recording, reproducing, and erasing information is controlled based on the pre-recorded area detection signal, so that the timing of recording, reproducing, or erasing can be accurately determined.

Note that timing control may be performed based on both the pre-recorded area detection signal according to the present invention and the conventional synchronization detection signal. In that case, even if an error occurs in the synchronization detection signal, the pre-recorded area detection signal will be output almost at the same position as the pre-recorded information such as the sector mark, so there will be no time lag and the pre-recorded area detection signal will Based on this, accurate timing control can be achieved.

[Embodiment 1] An embodiment of the present invention will be described below based on FIGS. 1 to 17.

FIG. 2 shows a magneto-optical disk IO as an example of an optical memory element that performs one recording, reproduction, and erasure by the information recording and reproducing apparatus of this embodiment. This magneto-optical disk 10 includes a spiral or concentric trunk l1, and each trunk l1 is divided into a plurality of sectors l2 along the circumferential direction. A preformant section 13 is provided in the leading area of each sector 12, and the remaining area is a magneto-optical signal section 14.

As shown in FIG. 3, in the preformat section 13, marks 15, 15, . Marks 16, 16, consisting of magnetic signals...
and a non-mark, which is a blank space between them, can be recorded. The marks 15, 15, etc. mentioned above are engraved in advance and cannot be erased, but the marks 16, l6
... can be recorded and erased. In addition, each mark 1 above
One of 5 and 16 and the non-mark between them corresponds to the signal "1", and the other corresponds to the signal "0".

FIG. I3(a) shows the sector format that is the format of each sector l2. The preformat section 13 is
A sector mark part 13a for taking synchronization timing in units of 12 sectors, and an I containing address information of sector 12.
It consists of a D section 13b.

On the other hand, the magneto-optical signal section l4 is composed of a data section 14a for recording magneto-optical signals and gap sections 14b and 14c. Basically, data is recorded in the data section 14a using marks 16, 16, . . . and non-marks based on magneto-optical signals. In the gap portions 14b and 14c, the recording start position and the recording end position are shifted back and forth due to a phase error that occurs between the rotation of the spindle motor for rotating the magneto-optical disk 10 and the synchronization timing of the above 12 sectors. This is an area that allows for some margin in case of a certain situation.

As shown in FIG. 4, the information recording and reproducing apparatus of this embodiment is as follows:
The information reproducing circuit l7 is provided with an information reproducing circuit l7.
From then on, a reproduced signal including the sector mark signal F is sent to the synchronization detection circuit l8, as will be described in detail later.

Further, a pre-recorded area detection signal G, which will be described in detail below, is sent from the information reproducing circuit 17 to a timing control circuit 20 as timing control means, and is also generated by the synchronization detection circuit 18 based on the sector mark signal F. The synchronization detection signal ■, which will be described in detail below, is sent to the timing control circuit 20, and based on these, the timing control circuit 20 outputs the reproduction timing signal ■ to the information reproduction circuit I7,
Recording/erasing timing signal J to information recording/erasing circuit 2l
is now output.

As shown in FIG. 5, the information reproducing circuit 17 includes a waveform shaping circuit 22 and a pre-recorded area detection circuit 24 consisting of a retriggerable pulse generation circuit 23, and includes a pre-recorded area in which sector marks etc. are pre-recorded. Detection of the format section 13 is performed as follows.

That is, the preformat section l of the magneto-optical disk 10
The reproduced analog signal K (see FIG. 1(a)) reproduced from 3 is input to the waveform shaping circuit 22, where the reproduced digital signal L (see FIG. 1(b) ) is converted to ). This reproduced digital signal L is manually input to the pre-recorded area detection circuit 24,
When a pulse exists in the reproduced digital signal L, the pre-recorded area detection circuit 24 outputs the pre-recorded area detection signal G for τ seconds.
(See figure (c)) is assumed to be the old GH. Since the pre-recorded area detection circuit 24 is composed of the retrigger pulse generation circuit 23, if the next pulse is manually inputted within τ seconds after the previous pulse is manually inputted in the reproduced digital signal L, τ will continue to be generated. The second pre-recorded area detection signal G is the old gh.

FIG. 6 shows one configuration example of the retriggerable pulse generation circuit 23. Here, the retriggerable pulse generation circuit 23 is kept in check by a one-shot multi-by-break 25. The time τ for setting the pre-recorded area detection signal G to the old gh is:
It is set by resistor R and capacitor C. in particular,
Then it is proportional to RC.

FIG. 7 shows an example of a structure in which a shift register 26 is used as the retriggerable pulse generation circuit 23.

The serial human power input to the human power terminal IN is assumed to be old gh, a clock signal of frequency fC is input to the clock terminal CK, and the Nth output of the shift output terminal QN is used as the pre-recorded area detection signal G. Also, the reproduced digital signal L is connected to the clear terminal C.
It is input to L. In this case, τ−Nx(1/f,)
becomes.

FIG. 8 shows an example in which an N frequency division counter 27 is used as the retriggerable pulse generation circuit 23. The reproduced digital signal L is input to the clear terminal CL, and the output of the output terminal 01JT is used as the pre-recorded area detection signal G. This pre-recorded area detection signal G is also input to one input terminal of the AND circuit 28. Further, a clock of frequency fc is input to the other input terminal of the AND circuit 28, and an output signal of the AND circuit 28 is input to the clock terminal CK of the N frequency division counter 27. In this case as well, τ=NX (1/fc).

In FIGS. 1A to 1C, in the preformant section 13 of the magneto-optical disk 10, there is a group of pulses based on marks 15, 15, . . . formed by concave and convex bits in the reproduced analog signal K. This is binarized by the waveform shaping circuit 22 and is the reproduced digital signal L. Amplitude detection, peak detection, etc. are used as a means of binarization. Here, when one pulse is input in the reproduced digital signal I7, the time τ during which the pre-recorded area detection signal G becomes the old gh in the pre-recorded area detection circuit 24 is the maximum pulse interval of the pulse group in the reproduced digital signal L. hA T m-,
is set to be larger. As a result, the pre-recorded area detection signal G, which is the output signal of the pre-recorded area detection circuit 24, becomes as shown in FIG. 1(C), and the reproduced analog signal K
A signal approximately equal to that in the briformant section 13 where the pulse group exists is obtained.

A more detailed configuration example of the information reproducing circuit 17 will be described below based on FIG.

Reproduction analog signal K reproduced from magneto-optical disk 10
is input to the buffer amplifier 30 in the information reproducing circuit 17. The reproduced analog signal K' amplified by the buffer amplifier 30 is input to a magneto-optical signal waveform processing section 31 and a preformat waveform processing section 32. Magneto-optical signal waveform processing section 3
1 and the briformant waveform processing section 32 are each constituted by the aforementioned waveform shaping circuit 22 (FIG. 5).

The magneto-optical signal waveform processing section 31 and the preformat waveform processing section 32 output signals corresponding to the marks 16, 16, 15, l5, etc. of the magneto-optical signal section l4 and the preformat section 13, and the non-marks between them. Reproduction digital signals L1-L2 as binary signals are output, respectively.

The reproduced digital signals L1 and L2 are input to the data companion section 33, and the PLL (Phase
Locked Loop), synchronous data M synchronized with the clock is output and sent to a demodulation circuit (not shown). Further, the preformant waveform processing section 32 generates a sector mark signal F based on the sector mark section 13a, and sends it to the synchronization detection circuit 18 (FIG. 4).

The Shinkyu processing control unit 34 outputs various control and timing signals N, 0, P, and Q to the buffer amplifier 30, magneto-optical signal waveform processing unit 31, briforma soto waveform processing unit 32, data synchronization unit 33, etc. It has become. or,
The signal processing control section 34 includes the pre-recorded area detection circuit 24 (FIG. 5), which outputs a pre-recorded area detection signal C based on the reproduced digital signal L from the data synchronization section 33. It is supposed to be done. Furthermore, a reproduction timing signal I is input to the signal processing control section 34. Next, Figure 10~
A more detailed example of the structure of the synchronization detection path 18 will be described based on FIG. In FIG. 10, the sector mark signal F output from the information reproducing circuit 17 is input to the sector mark detection circuit 35 in the synchronization detection circuit 18. This sector mark detection circuit 35 detects the sector mark portion 13a.

That is, as shown in FIG. 11, the sector mark detection circuit 35 detects the counter No. 1~No. The sector mark signal F output from the information reproducing circuit 17 is provided with a counter circuit 36 consisting of a counter circuit 36 and a judgment circuit 37 consisting of a counter No. 9. 1~
No. 9 will be powered by humans. These counter no. l-N
o. The output signals (1) to (V9) of 9 are each manually input to the determination circuit 37, and based on these, the determination circuit 37 outputs the sector mark detection signal R.

FIG. 12 shows counter No. 1~NO. 9 is a diagram illustrating the operation of FIG. In the sector mark portion 13a, as shown in FIG.
As shown in b), the aforementioned marks ]5, 15, . . . and non-marks between them are recorded. In this example, the same figure (a)
If the ratio of mark length and non-mark length is 5.3, 3,
Mark 15/15 so that it becomes 7, 3, 3, 3, 3.5
...is engraved. These marks 15.15.
. . . and the sector mark signal F obtained from the non-mark pattern ((C) in the same figure) is 0'0' in the mark 15, 15 . . . part and "1" in the non-mark part. The reproduced signals of these marks l5, 15, . . . and non-marks are transmitted to counter No. 1 in FIG. 1-No. When entered in 9,
As shown in FIG. 12(e), first, counter No.
1, the mark length of the first mark 15 is counted. Then, the count number ((d) in the same figure) is the mark length “5”.
”, it means that the first mark 15 has been detected.Subsequently, the counter NO.
．． 2, a non-mark with a non-mark length of "'3" is detected. Below is the counter No. 3~NO. At No. 8, marks 15, 15, . 9 marks length '5
” is detected.

These nine marks 15, 15, . . . and non-mark detection signals v1 to 9 are input to the determination circuit 37. Then, whether or not these nine detection results match the pattern of the sector mark portion 13a and whether each mark l5, l5,
. . . and whether or not the order of non-marks is appropriate is determined. As a result, only when the length and order of each mark 15, 15, . . . and non-marks are appropriate, the sector mark detection signal R becomes Low level, indicating that a sector mark has been detected.

In FIG. 10, the sector mark detection signal R is input to a counter 38, a timer circuit 40, and a determination circuit 41, respectively. The output signals S-T of the counter 38 and the timer circuit 40 are respectively input to the switch circuit 42, and the timing judgment signal H from the judgment circuit 41 is input as described below.
2, one of them is selected and output as the reference timing signal U. This reference timing signal U is also input to the magneto-optical signal section determination circuit 43, and based on it, a first magneto-optical signal section determination signal H1 is output as will be described in detail below.

An output signal W from the timer circuit 40 is further input to a window generation circuit 44, which will be described in detail below. The output signal X of the window generation circuit 44 is input to the determination circuit 41 .

The determination circuit 41 outputs a timing determination signal H2 as described below based on the output signal X and the sector mark detection signal R from the sector mark detection circuit 35.
This timing determination signal H2 is sent to the switch circuit 42 and the timing control circuit 20.

The timing control circuit 20 outputs the recording/erasing timing signal J and the reproduction timing signal I in FIG. 4 based on the reference timing signal U, the first magneto-optical signal section determination signal H1 and the timing determination signal H2. Ru.

FIG. 13 is a drawing showing the waveforms of each signal in FIG. 10. The sector mark detection signal R (FIG. 13(b)) becomes Low level when the sector mark section 13a in the preformat section 13 is detected. This sector mark detection signal R
The falling edge of is the synchronization timing of sector l2. The counter 38 in FIG. 10 sets the output signal S (FIG. 13(C)) to the LO-level after a predetermined count of 1 from the above-mentioned edge.

On the other hand, the count number of the timer circuit 40 is set to be larger than the count number of the counter 38 by one sector 12. Therefore, the output signal T of the timer circuit 40
The falling edge (FIG. 13(d)) almost coincides in timing with the falling edge of the output signal S of the counter 38 in the next sector 12.

In addition, the output signal X of the window generation circuit 44 ((e) in the same figure)
) is L with a predetermined window width near the falling edge of the sector mark detection signal R in the next sector l2, based on the falling edge of the sector mark detection signal R.
It is set to be at the OW level.

Timing determination signal H2 (
(r)) shows the output signal X of the window generation circuit 44.
If there is a falling edge of the sector mark detection signal R when is at Lo- level, it becomes the old gh level, and conversely, when the output signal It is set to be at a low level if it does not exist. Therefore, the timing determination signal H2 is transmitted to the sector mark portion 13a.
This serves as a signal for determining whether or not the detection has been performed within a predetermined range.

In the switch circuit 42 of FIG. 1O, when the sector mark part 13a is detected, the output signal S of the counter 38 is output, whereas when the sector mark part 13a cannot be detected, the output signal S of the timer circuit 40 is output. Signal T is selected. Therefore, the reference timing signal U (Fig. 13(g))
Even if a detection error occurs in the sector mark portion 13a, the timing at which the sector mark portion 13a should be detected can be outputted without any problem based on the output signal T from the timer circuit 40.

The magneto-optical signal section determination circuit 43 to which the reference timing signal U is input is a type of counter, and the first magneto-optical signal section determination signal Hl (FIG. 13(h)) is supplied to the magneto-optical signal section 14.
becomes Low level. That is, the first magneto-optical signal section determination signal H1 is a signal for discriminating between the preformanote section 13 and the magneto-optical signal section 14. The above-mentioned 14 timing signals U, timing determination signal H2, and first magneto-optical signal section determination signal Hl are sent to the timing control circuit 20.

Next, a detailed configuration example of the timing control circuit 20 will be shown.

In FIG. 14, the pre-recorded area detection signal G is input to the first counter 45 in the timing control circuit 20. The output signal Y of the first counter 45 is input to the second counter 46. The output signal of the second counter 46 becomes a Low level in the magneto-optical signal section l4 as will be described in detail below, and this becomes the second magneto-optical signal section determination signal AA. The second magneto-optical signal section determination signal AA is input to the Suinochi circuit 47.

The first magneto-optical signal section determination signal 1{1, which is the synchronization detection signal H, and the timing determination signal H2 are also input to the Suinochi circuit 47, and the first
The magneto-optical signal section determination signal H1 and the second magneto-optical signal section determination signal AA are switched and outputted as a reproduction timing signal I, which is sent to the information reproduction circuit 17.

As shown in FIG. 15(b), the pre-recorded area detection signal G input to the first counter 45 becomes the old gh level in the preformer note section 13, as explained based on FIG. The rising engine is the brifomanoto part l
It becomes almost the same as the starting position of 3. If the pre-recorded w4 area detection signal G remains at the old GH level continuously for a certain length (for example, 17 bytes) or more, as shown in FIG. 15(C),
The output signal Y of the first counter 45 changes from the low level to the old g.
It is set to be h level. That is, the first counter 45 determines whether or not it is the pre-former sorting section 13 based on the length of the pre-recorded area detection signal G.

Based on the rising edge of the first counter 45, the second counter 46 operates as shown in FIG. 15(d). Then, the briformant section 13 and the magneto-optical signal section 14
(for example, near the boundary between the
4b), the second magneto-optical signal section determination signal AA, which is the output signal of the second counter 46, is set from the Illight level to the Low level. Again, near the boundary between the magneto-optical signal section 14 and the briformant section 13 (
For example, from the Lo- level to the old GH at the gap 14c).
Return to level. This second magneto-optical signal section determination signal AA is therefore a timing signal created based on the pre-recorded area detection signal G.

Note that in the timing control circuit 20, the above-mentioned first
In place of the second counters 45 and 46, a one-shot multi-high break may be used.

FIG. 16 shows a detailed configuration example of the switch circuit 47.

First magneto-optical signal section determination signal H1 which is the synchronization detection signal H
is input through the inverter 48 in the switch circuit 47 to the clock input terminal CK of the flip-flop knob 50 (for example, 74LS74 manufactured by Texas Instruments, USA). Further, the timing determination signal H2 is inputted as it is to the data input terminal D of the Furinoburosub 50. The output signal BB of the output terminal Q is input to both input terminals of the NAND circuit 51, and the output signal CC of the output ζ·M1 child Q is input to one input terminal of the NAND circuit 52. Further, the second magneto-optical signal section determination signal AA is inputted to the other input terminal of the NAND circuit 52. Output signals DD − of these NAND circuits 51 and 52
EE is input to the NAND circuit 53, and the NAND circuit 5
The output signal No. 3 becomes the reproduction timing signal I.

FIG. 17 shows the waveforms of each signal in FIG. 16. 1st
The magneto-optical signal section judgment signal Hl (Fig. 17(C)) and the second
The magneto-optical signal section determination signal AA (section (e) in the same figure) becomes a Low level in the magneto-optical signal section 14 (see (a) in the figure). When the timing determination signal H2 ((b) in the same figure) is captured at the falling edge of the first magneto-optical signal portion determination signal Hl, the output signal BB ((d) in the same figure) from the output terminal Q of the flip-flop 50 is detected. can get. When this output signal BB is at the old gh level as shown by the solid line, the sector mark portion 13a
If the detection is normally performed and the level is low (as shown by the dotted line), an error has occurred.Then, the circuit of FIG. 16 uses the flip-flop 5 as the reproduction timing signal I.
When the output signal BB of the output terminal Q of 0 is at Fly level, the first magneto-optical signal section determination signal H1 is output, and when the output signal BB is at Low level, the second magneto-optical signal section determination signal AA is output. It is supposed to be done. Therefore, even if an error occurs in the detection of the sector mark portion 13a, the timing can be compensated for by the pre-recorded area detection signal G.

For example, the following control can be performed using the reproduction timing signal I described above.

First, the reproduction timing signal I is used to switch the input signal to the PLL in the data synchronization section 33 in FIG. That is, as shown in FIG. 9, in the case of the magneto-optical disk 10, the magneto-optical signal waveform processing unit 3l and the pre-format waveform processing unit 32 process marks 15 and 1 in the reproduced analog signal K'.
5... and marks 16, l6... are subjected to waveform processing separately, so at the time of inputting to the PLL in the data synchronization section 33, the reproduced digital signals L1 and L2 after waveform processing are switched and input. There is a need.

Second, it is important to check whether the signal of the magneto-optical signal section 14 or the address information of the preformat section 13 is being demodulated during demodulation by a demodulation circuit (not shown) provided after the data synchronization section 33. The above reproduction timing signal I is used for the determination.

Thirdly, when a playback abnormality occurs, it is necessary to detect and output it. The reproduction timing signal I is used for this purpose. In the first to third examples above, a common element is determining whether the signal is in the magneto-optical signal section l4 or the preformat section 13.

The above pre-recorded area detection signal G is from the pre-format unit 1
In addition to supplementing the timing control by detecting the sector mark portion 13a within 3, the magneto-optical signal portion 14 can also be used in the following cases.

That is, it can be used as a read gate of the PLL in the data synchronization section 33. Also, AGC (Auto
matic Gain Control), AGC is used only in the area where data is recorded.
This can be used to turn on the signal and hold it otherwise. Furthermore, it can be used to detect burst errors in recording signals. In the above three examples, the common element is that the magneto-optical signal section 14 or the format section 13 determines whether or not the area is recorded with information. Therefore, these can be used not only for the preformat section l3, which is a pre-recording section, but also for the magneto-optical signal section 14, where information is recorded, reproduced, and erased.

[Example 2] Next, a second example will be described based on FIGS. 18 to 20.

In this second embodiment, when a defective pulse as shown by the dotted line S or t in FIG. Figure 1 (C
) as shown by the dotted line U or V, the pre-recorded area detection signal G
This measure was taken to prevent errors from occurring in the reproduction of information due to erroneously identifying it as the old GH.

That is, the pre-recorded area detection circuit 24 included in the information reproducing circuit 17 is composed of a suitable retriggerable pulse generation circuit 54 and a leading pulse removal circuit 55, as shown in FIG. The leading pulse removal circuit 55 is a circuit for invalidating the output of the retriggerable pulse generating circuit 54 for the leading M pulses in the reproduced digital signal L. FIG. 19 shows a specific example of the configuration of the leading pulse removal circuit 55. Here, an M-ary counter 56 is arranged as a leading pulse removal circuit 55 in the preceding stage of the retriggerable pulse generation circuit 54, and the M-ary counter 56 removes the leading M pulses in the reproduced digital signal L. . Note that an M shift register may be used in place of the M-ary counter 56 described above.

FIG. 20 shows another example of the structure of the leading pulse removing circuit 55. Here, a shift register 57 as the leading pulse removing circuit 55 is arranged after the retriggerable pulse generating circuit 54, and a retriggerable pulse generating circuit 55 is arranged. The output of the circuit 55 is input to the clear terminal CL of the shift register 57, and the reproduced digital signal 1- is input to the clock terminal CK of the shift register 57.
is input, and the M-th shift output QM is set as the recorded area detection signal q G r .

Here, M=1, that is, the reproduced digital signal L. The tie-strapping control will be explained by taking as an example a case in which the output of the 1-writable pulse generation circuit 55 is invalidated for only the first pulse.

As shown in FIG. 1(a), if the defective pulse in the area where information is not recorded is only 1 pulse, this defective pulse is treated as a sea bream effect by the leading pulse removal circuit 55, so as shown in FIG. 1(d). As shown in
・Based on the pulse, the pre-recorded area detection signal G' is
In addition, in the pre-formant section 13, the timing at which the pre-recorded area detection signal G' becomes If i g h is delayed by one pulse.
As for the read gate timing with respect to L, a delay of several pulses does not have any adverse effect.

Therefore, the reliability of PLL operation does not deteriorate.

In the above embodiment, an apparatus for recording, reproducing, and erasing information on a magneto-optical disk 10ζ was taken as an example, but the present invention is also applicable to an apparatus that only reproduces various optical memory elements, or a write-once type apparatus. can also be used. Furthermore, the present invention can also be applied to an information recording/reproducing apparatus for a magnetic memory element or the like in which a group of information pulses indicates a recorded area in addition to an optical memory element.

〔Effect of the invention〕

As described above, the information recording and reproducing apparatus according to the present invention is an information recording and reproducing apparatus that records or reproduces information in an optical memory element, and includes a prerecorded area detection circuit that detects a prerecorded i area in which information is recorded in advance. , and timing control means for controlling the timing of recording or reproducing information based on the pre-recorded area detection signal output from the pre-recorded area detection circuit. As a result, the timing of recording, reproducing, and erasing information is controlled based on the pre-recorded area detection signal, so that the timing of recording, reproducing, or erasing can be accurately determined.

Note that the timing control may be performed based on both the pre-recorded area detection signal according to the present invention and the synchronous detection signal of Yoto. In that case, even if an error occurs in the synchronization detection signal, the pre-recorded area detection signal i will be output almost at the same position as the pre-recorded information such as a sector mark, so there will be no time lag, and this pre-recorded area detection signal This has the effect that accurate timing control can be realized based on the .

[Brief explanation of drawings]

1 to 20 show an embodiment of the present invention. FIGS. 1(a) to 1(d) are time charts showing the procedure for generating a pre-recorded area detection signal. FIG. 2 is a +a schematic plan view showing the magneto-optical disk. FIG. 3 is an enlarged view of the main part of FIG. 2. FIG. 4 is a block diagram of the information recording/reproducing apparatus. FIG. 5 is a block diagram of the information reproducing circuit. 6 to 8 are explanatory diagrams showing specific examples of retriggerable pulse generation circuits, respectively. FIG. 9 is a block diagram showing the detailed structure of the information reproducing circuit. FIG. 10 is a block diagram showing the detailed structure of the synchronization detection circuit. FIG. 11 is a block diagram showing the detailed configuration of the sector mark detection circuit. FIGS. 12(a) to 12(e) are explanatory diagrams showing the operation of the counter circuit. FIG. 13 is a time chart showing the transition of each signal in the synchronization detection circuit. FIG. 14 is a block diagram showing the detailed structure of the timing control circuit. FIG. 15 is a time chart showing the transition of each signal in the timing control circuit. FIG. 16 is a circuit diagram showing the detailed structure of the sinch circuit. FIG. 17 is a time chart showing the transition of each signal in the switch circuit. 18 to 20 show a second embodiment. FIG. 18 is a block diagram of the information reproducing circuit. FIGS. 19 and 20 are explanatory diagrams showing specific examples of the pre-recorded area detection circuit. FIG. 21 is a block diagram showing a conventional information recording/reproducing device. 20 is a timing control circuit (timing control means);
4 is a pre-recorded area detection circuit, and G is a pre-recorded area detection signal.

Claims (1)

[Scope of Claims] 1. An information recording and reproducing apparatus that records or reproduces information in a memory element, comprising: a pre-recorded area detection circuit that detects a pre-recorded area in which information is recorded in advance on the memory element; 1. An information recording/reproducing apparatus comprising: timing control means for controlling the timing of recording or reproducing information based on a pre-recorded area detection signal output from a recording area detection circuit.